The material, composed of ceramic nanoribbons embedded onto silicone rubber sheets, generates electricity when flexed and is highly efficient at converting mechanical energy to electrical energy. Shoes made of the material may one day harvest the pounding of walking and running to power mobile electrical devices. Placed against the lungs, sheets of the material could use breathing motions to power pacemakers, obviating the current need for surgical replacement of the batteries that power the devices.

The Princeton team is the first to successfully combine silicone and nanoribbons of lead zirconate titanate (PZT), a ceramic material that is piezoelectric, meaning it generates an electrical voltage when pressure is applied to it. Of all piezoelectric materials, PZT is the most efficient, able to convert 80 percent of the mechanical energy applied to it into electrical energy.

"PZT is 100 times more efficient than quartz, another piezoelectric material," said Michael McAlpine, an assistant professor of mechanical and aerospace engineering at Princeton, who led the project. "You don't generate that much power from walking or breathing, so you want to harness it as efficiently as possible."

Fans of sf are waiting for devices that let us harvest power from our ordinary activities - waiting ever since Frank Herbert wrote about power-harvesting stillsuit in his 1965 novel Dune:

It's basically a micro-sandwich; a high-efficiency filter and heat-exchange system. The skin-contact layer is porous. Perspiration passes through it, having cooled the body. Motions of the body, especially breathing, and some osmotic action provide the pumping force. With a Fremen suit in good working order, you won't lose more than a thimbleful of moisture a day - even if you're caught in the Great Erg.